06 King Quad timing

Hi guys. I have a problem where the quad will start and run well for about 5 minutes and then it dies. On inspection the airbox has oil in it (quite a lot). The oil is pumping through the cylinder head breather hose. This problem first happened suddenly. I have since done the top end including, piston, gaskets, rings and valves. I have also done the carb (not that I thought that this was the problem). The compression seems normal. The only thing that I can think of, is that I did not grind the valves well enough. Anyone experienced this? If so, how did you fix it? Any other thoughts?

What should I do about this , bad oil leak where the filter cover bolts on . Can I use some gasket maker 

Hello everyone, I just picked up an 02 LT-F250F the other day and have been in the process of tearing it down to fix some stuff- one of which was the cylinder base gasket leaking like a sieve. Well, I know why that is now, and I also discovered that someone had been in there before. I didn't take pictures, but it looks like it was probably run low on oil at some point, the cam journals and the "bearings" (for lack of a better term) in the head and the valve cover are totally wiped out, very deep grooves.  From what I know it's very difficult to repair aluminum in this way, so I'm trying to figure out where to go next.
 
1. Have someone grind down the head and valve cover and fit actual bearings in since the aluminum is screwed, and have the cam ground down to match.  I have no idea what this would cost.
2. Buy a replacement head+cam+valve cover.
 
#1 I was hoping someone might have some advice on, but #2 seems like it'll (probably) be the more cost effective option.  However I'm running into some difficulty, it seems like the 2001 and 2002 models specifically use a different head part number,  11100-19B10, instead of  11100-19B01 like for all earlier models.  What exactly is the difference between them? There are obviously far more of the earlier heads because it ran for over 10 years.  Are they actually interchangeable? I've also noticed there are heads from the LT250EF that has 4 valve heads but also otherwise look identical.  Would those work as well possibly?  I'd like to not have to drop $500 on machine work or new heads on a $1300 quad that I'm already putting a bunch of new parts on.  Oh, and it has a new piston and the cylinder itself looks pretty good too, as I said someone was in here before me.
 
Any help or advice would be greatly appreciated. I'll post pics of the carnage tomorrow.
   
 

should i run a thicker oil in a older quad because it make a little more noise than usual 

I have a 2016 Arctic Cat 500 and recently noticed some oil leaking on the engine block to the right of the oil filter. It's near two metal lines going in and out of the engine block. I think one of the lines is called an engine oil line. I have a photo I'm going to try and attach. Any help would be greatly appreciated. I don't want to start tearing into the engine if I don't have to. I think maybe a gasket or something blew around one of these lines. The ATV runs fine otherwise. Doesn't overheat or anything.